When Potter and Charles are playing gin in the tent Charles says 54 points record. He then reaches for a notepad but in the next scene he is already writing on it. The notepad then disappears and reappears on the table between shots.
Throughout the episode, Loretta Swit's fingernails can be seen at almost an inch long. No nurse, especially a head nurse, would have fingernails that long.
When Winchester plays the record and Potter takes it off the turntable the person who throws it is not Potter but a stand in. You can tell since the person is much taller than Potter is.
When Potter comes down with the mumps, a replacement surgeon is sent for because a lot of wounded are expected. But when Winchester also gets sick, a second replacement is not sent for.